Buffing wheel section



rwr" April 22, 1952- Filed July 17, 1951 E. W.- HALL BUFFING WHEELSECTION 2 SHEETS-SHEET 1 April 22, 1952 w, HALL BUFFING WHEEL SECTION 2SHEETSSHEET 2 Filed July 1'7, 1951 I 34: E'Zsa Wilda,

flat F 2 Patented Apr. 22, 1952 UNITED straps Claims.

This invention relates to bufiing wheels and in particular to aso-called section adapted to be assembled on a spindle with other likesections to form a wheel of the desired length of face. The object ofthe invention is to provide in such a section inbuilt means whereby byvirtue of the way in which the sections are assembled, difierentdensities of the working face of the wheel may be obtained. For thispurpose obverse and reverse sides of the section at a location inwardlyof its periphery are provided with bearing parts which aredifferentially former on the sides 'respectively, so that whentwo likesides of two sections are presented one to the other, the central'planesof the'two sections will be spaced by a determined amount, whereas ifunlike sides are presented one to the other, the spacing will bedifferent. I have used the words obverse and reverse which, however,merely are a convenient identification of the two sides of the section,to avoid the uncertainties of referring to one and the other," but thewords are not otherwise significant.

The invention will be well understood by reference to the followingdescription taken in connection with the accompanying drawings, wherein:

Fig. 1 is a side elevation of the section showing the obverse side;

Fig. 2 is a similar view showing the reverse side;

Figi 3 is a fragmentary section in a radial plane showing theconfronting sides when two like faces are apposed to each other; V

. Fig. 4 is a, similar view showing two unlik faces apposed to eachother; and

Fig. 5 is a diagrammatic View to illustrate thebearings provided betweenthe two sections when unlike faces are apposed to each other.

Referring to the drawing there is there shown a buiiing wheel section ofknown type, generally in the form of a thin cylindrical disc andcomprising a relatively rigid central portion including a hub I 0 (Figs.3 and 4 conveniently formed or chipboard, pierced at 12 to receive thespindle and encircled by'an annular mass of abrading material [4, hereinformed of a'number of plies of fabric so arranged as to present. rufilesor pleats at the periphery of the section. Side plates l6 of thinvulcanized fiber overlie the sides of the hub-and the inner portion ofthe abrading mass. These parts may be secured together by suitableadhesive. In assembling and uniting theparts under pressure, an annularridge E8 may be formed inthe'sidepl'ates to interlock with the abradingmeans. When a number of these sections are assembled side by side andclamped on a spindle, the clamping plates usually grip the assembly atthe inner part of the buffing annulus M, conveniently substantially atthe location of this ridge 1%. A section having a construction as so fardescribed is not new and it serves merely as an illustration of one kindof section to which the invention may be applied.

In the example of the invention shown, the obverse face of the sectionas seen in Fig. 1 is provided with a series of regularly spacedprojections 260 and the reverse face of the section as seen in Fig. 2with a series of regularly spaced projections 202". I indicateconventionally in Fig. 1 the color black on side plate l8 of the obverseside and in Fig. 2 the color red (suggestive of reverse) on the reverseside, further to distinguish arbitrarily the two faces. In practicemoreover, the two side plates 16 may actually be colored in contrastingcolors for ready.

differentiation.

In the present example the various projections are identical in size andshape and their position is at the same radial distance from the center,their differentiation for purposes of the invention being obtained bytheir relative circumferential spacing which implies a difference innumber, there being in the example shown twenty onthe obverse side andsixteen on the reverse side.

The projections 280 and 201' are here shown as circular and more or lessdome-shaped embossments formed by suitable dies when the section ismaderunder axial compression. Herein they are shown as arranged on theridges l8 which is not significant, since so .iar as the correlation .ofthe projections is concerned, the top of this ridge may beconsideredmerely as a part of the end surface of the inner portion ofthe section. It may benoted however, that when formed as hollowembossments as herein opposite the inner portion of the abrading mass Ma portion of the latter is pressed into the concavities of the embossedprojections and forms an interlock resisting both radial andcircumferential displacement and that this mass of material supports thewall of the hollow projections against axial compression exerted thereonwhen the sections are clamped.

The size and spacing of the projections on the obverse side (see Fig. 1)are such that when the obverse sides of two like sections are presentedone to the other with the projections out of line, then as illustratedin Fig; 3, the projections 2% on one will enter between the projections290-bp 3 the other. In other words, the projections will axiallyoverlap. In the present instance, partly because of the dome form of thesections which causes them to decrease in circumferential widthoutwardly, the overlapping is complete and the ends of the projectionsrest on the base surface from which the projections of the opposingsection arise. I consider such a construction preferable to one whereintapered projections nesting would hear on one another laterally withclearances at the crests. The arrangement may be described by sayingthat the sum of the circumferential Widths of the projections is notgreater than one-half the circumference so that theintervening spacespermit the entry thereinto of the projections of an adjacent section.The space between the central planes of two assembled sections is thusin the example shown twice half the thickness of the sections asmeasured between the crests of the ridges is plus the height of aprojection 2B0.

- The projections 291- of the reverse side are of the same size as theprojections 290 but spaced further apart circumferentially because theirnumber is smaller. Clearly they will similarly overlap axially when tworeverse sides are presented to each other. Except for the referencenumerals Fig. 3 would represent such an arrangement.

To provide for a different spacing when a reverse and observe side areapposed, the circumferential length of the spaces intervening betweenadjacent projections 2hr on the reverse side is greater than thatbetween adjacent projections 200 on the obverse side, but less than thesum of such space on the observe and the circumferential width of aprojection 290 adstantially centered between two projections 26o and isin line with the space between them, and if we were concerned solelywith these three projections the overlying projection couldpass inbetween the other two as is seen in Fig. 3. Passing clockwise however tothe next adjacent projection 291' shown in dot-and-dash. lines, it

willbe seen that this gains on the full line pro-.

jections 200 and overlaps to a certain extent the underlying projection2B0 toward its left. The next projection 201' in the series gainsfurther and at the twelve oclock position the projections Zilr and 200are in alignment. The next projection 2B1" passes further across theface of the projection 290 immediately beneath the same and at thehalf-past one position the cycle is complete and the projection 251' iscentered between two of the projections 280. This repeats itself aroundthe circle in four complete cycles, two of which are illustrated, theprojections at the 9, 12 and 3 oclock positions being in alignment andthose immediately adjacent thereto at either side being in partiallyoverlapping position. If we change the relative position of the twosections as by a movement equivalent to a in Fig. 5, the projections inthe 12 oclock position will no longer be exactly aligned. The amount ofoverlap of the pair to their right will be decreased, but that of thepair to the left increased and overlap may commence at the groupsformerly completely out of alignment. When the movement has continuedthrough an arc of 22 the relative position of the two groups consideredas such is the same as in the figure. By virtue of this arrangement whenthe obverse side and the reverse side of two adjacent sections arepresented one to the other the projections cannot nest as when likesides are presented to one another and as is seen in Fig. 3, butbearings are provided which hold the sections apart as seen in Fig. 4,and consequently provide for a lesser density of the wheel at theperiphery. The increase in spacing in the example shown is the altitudeof the projections The arrangement may be apprehended in terms of thenumber of projections, herein twenty on the obverse and sixteen on thereverse. The gaining or hunting eifect described in connection with Fig.5 is obtained when the least common multiple of the numbers ofprojections on the two sides contains relatively prime factors. If thesewere the only two factors the two numbers would be relatively prime andthe gain or hunting effect would occur gradually throughout thecircumference. Preferably as here the two numbers also have a commonfactor of three or more, herein four. In this instance the displacementof the elements of one series relative to the other occurs for eachgroup of five projections 200 and four projections 201', five and fourbeing the relatively prime factors of twent and sixteen respectively.This cycle occurs four times. in the circumference and therefore therelation of apposed projections is identical at distances 90: apart andthe bearing of sections one on another is thus balanced throughout thecircumference.

In assembling a wheel from these sections'we may put like faces togetherthroughout, producing a relatively dense periphery or unlike facesthroughout, producing a relatively soft periphery, or the spacing may bevaried to provide 'a' wheel with a relatively soft section which issometimes desired.

I am aware that the invention may be embodied in other specific formswithout departing be had tothe appended claims to indicate thosepriciples of the invention exemplified by the particular embodimentdescribed and which I desire to secure by Letters Patent.

I claim:

1. A buff section adapted for assembly onv a spindle side by side withother like sections to.

form a landin wheel said sectioncomprising relatively unyielding centerand an annulus; of abradin material encircling its p riphery andanchored thereto, the center having on its ob verse and reverse sides atsubstantially the same distance radially from the center annular seriesj. of spaced axially extending projections, at least outer portions ofthe projections extending over less than one-half the circumferencewhereby the projections on the obverse sides of two sectionsor those onthe reverse side may nest with slight clockwise revolution of theprojections 20x at least partial axial overlapping, the projections onthe obverse side and those on the reverse side being differentiallyspaced to provide circumferential overlapping of projections of twoadjacent sections assembled obverse to reverse.

2. A buff section adapted for assembly on a spindle side by side withother like sections to form a buifing wheel said section comprising arelatively unyielding center and an annulus of abrading materialencircling its periphery and anchored thereto, the center having on itsobverse and reverse sides at substantially the same distance radiallyfrom the center annular series of spaced axially extending projections,the circumferential extent and spacing of the projections in each seriesbeing such as to provide, when a side of a section is presented to thelike side of a like section, for entry of the projections of one sectionbetween those of the other with at least partial overlapping in theaxial direction, the number of projections on the obverse beingdifferent from the number on the reverse, the two numbers beingdifferent and their least common multiple having two relatively primefactors.

3. A buff section adapted for assembly on a spindle side by side withother like sections to form a bufiing wheel said section comprising arelatively unyielding center and an annulus of abrading materialencircling its periphery and anchored thereto the center having on itsobverse and reverse sides at substantially the same distance radiallyfrom the center annular series of spaced-axially extending projections,the circumferential extent and spacing of the projections in each seriesbeing such as toprovide, when a side of a section is presented to thelike side of a like section, for entry of the projections of one sectionbetween those of the other with at least partial overlapping in theaxial direction, the number of projections on the obverse beingdifferent from the number on the reverse, the numbers having a commonfactor at least as great as three and other factors respectively whichare relatively prime.

4. A buff section adapted for assembly on a spindle side by side withother like sections to form a bufing wheel said section comprisin arelatively unyielding center and an annulus of abrading materialencircling its periphery and anchored thereto, the center having on itsobverse and reverse sides at substantially the same distance radiallyfrom the center annular series of spaced axially extending projections,the projections of each series being regularly spaced, the sum ofcircumferential widths of the projections of each, series at least atthe crests being no greater than half a circumference, and thecircumferential length of the spaces intervening between adjacentprojections on the reverse side being greater than that between adjacentprojections on the obverse side but less than the sum of such a space onthe obverse and the ircumferential width of a projection adjacentthereto.

5. A buff. section adapted for assembly on a spindle side by side withother like sections to form a buiiing wheel said section comprising arelatively unyieldin center and an annulus of abrading materialencircling its periphery and anchored thereto, the center having on itsobverse and reverse sides at substantially the same distance radiallyfrom the center annular series of spaced axially extending projections,the pro-, jections of each series being regularly spaced, the sum ofcircumferential widths of the projections of each series at least at thecrests being no greater than half a circumference, the circumferentialWidth of two adjacent projections and of the space between them on theobverse side being greater than the circumferential width of the spacebetween adjacent projections on the reverse side.

ELISHA W. HALL.

No references cited.

